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Subj : Re: How to manage time-slicing in Pthreads programs?
To   : comp.programming.threads
From : Joe Seigh
Date : Sat Feb 19 2005 09:57 pm

On 19 Feb 2005 18:01:22 -0800, D'artagnan <musketeers@gmail.com> wrote:

> OK, maybe I didn't explain the situation clearly in my first post. In
> my example, I don't want thread A to put itself to sleep, I want thread
> B to put it to sleep and wake it up later.  Consider the following
> senario: thread A and thread B are processing a huge collection of
> items, one-by-one. The workload is split up between the two threads
> such that 99% chance there aren't conflicting accesses between the two
> threads.  For the 1% chance of conflicting accesses we need some
> protection. The problem is that thread A never knows which items will
> cause conflicting accesses, only thread B has this knowledge.
> Therefore, pthread_cond_wait() doesn't apply here because (1) thead A
> doesn't know when to wait; and (2) if thread B calls it and goes to
> sleep, there is nobody to wake it up.
>
> The desired scheme would be: When thread B becomes aware of a potential
> conflicting access, it puts thread A into sleep. Thread B finishes the
> access, then wakes thread A up. Are there any ways to do this? Thanks.
>
>
No, because there is no way for you to tell where thread A is and at
what point it will sleep after you tell it to.

-- 
Joe Seigh

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